Sijdrry feeder



f SLURRYFEEDER & rTierllan Incorporated, a corporation of HelavvareApplication April 4', vk19521, `Serial lNo. 280,686

` llclaims.; icl. .21o-n continuous` butlusuallysrnall; quantity of a,slurry such as .diatomaceous earth into the water as the latter goes tovthe filter. Thelter aid material so supplied continuously builds up alayer on the .filter septum to effectuate the filtration process, thefeed of slurry being thus constantly eieosive to.` keen a fresh outer,surface of thematerial at the s .ellturiit` Aparticularly convenient wayof, introducingfthe cliatonlacelous'earthv or. the like lis to make itas a relatively concentrated slurry, which vis then` fed into theliquidato bejltered, e. g'.4 into water which may be continuouslyflowing past, the locality of slurry introduction-j t s Eor these andlikefpurpose's and especially for installat tions-ot larger size, slurryfeeding has. usually been accomplished'with apparatusinvolvingconventional pumps .and check valves, arrangedto draw slurryfrom a reservoir'- and. advauCe it to the locality of introduction inthe flowing stream. Notonlydoesltyhe abrasivecharacter of.thefpartielesproduee 'rapiti weer of the conventional .mechanicalequipintent.;- but thelslurry constantly tends; to cloegthepuinp andthevarious clrraelcY valves, especially tfhela-tten Thatis to saytslurryparticles set into all t the Slldiugorheating. surfaces, oftenito` thepoint of stoppingthe, operation, ;and particularly collect in and aroundthe valves for impairmentof their function. Indeed durius closingmovements of the valves', the accumulating particles tend to prevent.propelseating, with the result of undesirable back, flow and .other.diliiciilties In order .to alleviate .these problems, the. slurry isusually established and witlldrawnv from. its reservoir in as dilute astate-as possible, but in. consequence the. reservoir must he. verlllarge and there musthe extraordinary lmeans lfor constant and vigorousagitation to 'keep the, rapidly. settling particles .in the necessarydilute suspension; then, to handle., the. dilute. .'slurry, vthe pumpingmeansT rnustv be of correspondingly larger Capacity--y Inoonse.que1;1ee, the, enti'le .-equpnlent, especially with the big slurrytank, isv ex- .tremely `bl ill ty, 1 cumbersome andv expensive; it istroublesome to makeup or. add 'furtherlquantities-of slurry; and despitethe usev of dilute ,sluniest dioulties. of clogging andfof poor. orimproper valve faction persist, all the time,

l requiring frequent shutdown, toroleaning or other servi'ce. i .i

Aocordinslyra .military ohieot of the present. inven-4ii'oli'isjto'igzrovide a slurry feeder wherein the above problems anddifficulties are effectively avoided or minimized,

2,733,814 YEfai'ientexif-l'elm 1c 1.955

feeding apparatus, Operableinan. automatic: and, essentiallycontinuousmanner yand without; appreciable `cliculty due to clogging, settling o1:abrading action. by thefsolid particles. Another object, is toafford-improved slurry feeders having positive, effective actionofvalves and other parts at all times, unhamperedl-by collectingpaxv-Vrieles of slurry, and. free of needl for frequientfrcleaning or otherattention to assure complete` clo,singaandopning action of the valves. l

A further object is to provide novell-slurryffeedingeap.-

paratus adapted to handle slurres havinga'nyeonebf a` wide range ofconcentrations, including Lvery'ahick-or heavy mixtures; and a corollaryobject; is toaforld such apparatus which may be. of -'11e1atively smalldimensions, needing only a small slurry tankandmeansof comparativelysmall capacityand size fordisplacing slurry-yet having an effectivelylarge capacity aszmeasured in 'actual amount of solid material fed.,

Additional objects include the provision. of such apparatus which may bereadily controlled "or adjusted :for accurate maintenance of; anydesired rate, ofieejcl, and likewise the provision of feedingapparatuswhich willrequire little 0l'` 1.10 service overflongperiods'oftirne. ,It is also an object to provide slurryv feeders ofmorevv-etiicient and reliable construction in a variety Qf, respects,and like wise to provide such feeders wherein thefsupply' oftslury maybe constantly maintained, indeed 4with, successive additions asnecessary from time `to time, fallf'without'interrupting the desiredfeeding operation.

To. these and other ends the4 naturepandV principlesfof the inventionmay be conveniently understood hyreference to the following; descriptionand1 the annexed drawing, which shows, in a manner simpliedifor betterillustration of underlying principles the fundamental elements andrelationships of one satisfactory embodiment. l

In the drawing:

Fig. l illustratesl somewhat c liagrammatically.theim .voir or as afluid supplylueans,A provided with aremovablc screen 11 adjacent thetop. The lower partfofithe slurry hopper forms a. tankhaving `anoutletport 12 in the side wall thereof towards thebottom. At the bottomof the tank there ris provided a 'rubber checkl valve :13 through whichagitating air may be. admitted; .f This air bubbles up through theslurry and, keeps the solid, particles in even suspension. To supplysuch agitating 'air a diaphragm-typeair compressor Muis-provided;Therco'mpressor is conveniently operatedf by aA cam 15 disposed upon ahigh speed shaft- 16, which is provided withfazpulley 17 adapted toreceive drive by a belt from a suitable `source of power, not shown.WQI'IIIl reduction .gearing'18 is also provided for operating a lowspeed shaft 19, i. Je. from the same, drive s haftlo. While otherarrangements such as mechanical stirring devices may be used foragitating the slurry supply 'in'the reservoir 10'to keep Ithepar-`ticles in more or less uniform suspension, the. air Yagitation affordedby means kof the, character just described is very effective in at leastmost cases and has therefore been-fillustrated by way of example. Itwill also be understood that the driving instrumeutalities, whileconvenient, Yare illustrative and that other means may be provided foractuating the several shafts or more specifically `the Acompressol 14and the various valve mechanisms hereinbel'ow described. t

Adjacent 'to the tank part of the slurry hopper there isa pumping anddilution chamber or receiving chamber 2 0. The port 12 connects theslurry hopperwith this chamber through a suction valve generallydesignated 2l. This valve andthe `'other valves preferably comprise anylon vseat.. portion 22.which cooperates with a rubber valve member 23.Valve part 23 is carried on a valve lever 24 which extends through aflexural rubberV seal 25 which 'forms 4a. lsurefor a portion'of theupper part of the di- -1ution^`andpumping chamber, i.-e.'adiaphragm-type seal Of-irbberforthe like1which permits the lever to rocka'bout its'pont'of egress from the' chamber. The valve 'lever24"is'preferablyifulcrumed in Vsuch rubber seal and -a't'its top 0r"outer end, the lever 24 is pivotally Yconnected -to the 'cam followerrod 26. Appropriate structure, such tasa-suitable spring 27- acting onthe rodY 26, normally "-tends tokeep the valve 23 against the seat 22.Valve follower rod 26 is operated by a cam 28 disposed on the low Aspeedcam shaft f f' For .withdrawing measured quantities of slurry from the"slurry.tank-"chamberfinto the pumping and dilution chamfber:20,-'adiaphragmpump 30 is in communication with .-thecharrber 20, e`.g.' opening directly into the chamber, `and :the diaphragm 30a of thispump is 'preferably me- Ichanically operatedfrom a cam 30h on shaft 19by the 'rod.3l. Toreturn the diaphragm to the right a suitable springmeans 31a is provided, e. g. a spring under comy pression, actingagainst a flange 31b fixed on or integral "wthvthe rod.31. 'bet adjustedby adjusting the position of the diaphragm-adjustoxi'ge'nerallydesignated 32, which constitutes a stop 'fortheflange 31b to limit the rightward travel of the dia- The stroke of thediaphragm 30a may .phra'gmrod 31. Assume diaphragm 30a in the extremeleft position andthen moved to the right (as shown in the.idrawing),"this movement ofthe diaphragm will Withdraw fslurry fromtheslurry tank and admit it into the pump- -ing'..and`dilution' chamber 20,provided suction Valve 21,

is open. Operation-of diaphragm 30a efectively varies -the .volumeo'fchamber 20, which is therefore sometimes referred to herein as avariable volume chamber.

fIn the operationlof this slurry feeder, dilution Water is -ztaken froma pipe or main 35 into which slurry is to be -ied,v andi. passed througha pipe 36 to a flushing valve chamber 37. This ushing valve chamber isin communication with the dilution chamber 20 through a ushing A-vallvegenerally designa-ted 38. Flushing valve 3S is generally like thesuction valveA previously described. It includes the rubber valveportion', the nylon seat, and it alsol `includes an operating lever 39which is fulcrumed in the -exural rubber seal 39a'(similar to the seal25) which -forms-'afclosure for the bottom of the ushing cham-:ber"`3.7. I l

Lever-'3)'is pivoted to a'eam follower rod 40 cooperatr'ingt-with:aicam'41 on'the'shaft' 19. kAdjacent the top or f'otherend'of vthedilution chamber there is another ush- ',ingzchamber 42 whichcommunicates with the water pipe A'ormain 35 through a pipe 43.

i? f-1`he"r'nai`n 'flow-pipe 35, intermediate the pipes 36 and 43, is:preferablylalthough not always necessarily) pro- '..Yidedzfwith a"restricted orice generally designated 44.

The Yflushing valve 46 is' generally like the valve 38 and is .operatedbyxthelever 47 which passes through (and is afulcrumedfin') Va exuralrubber seal 48 of the same type. .The lever 47 is pivoted to camfollower rod 4S which co- .operates with a cam 49 on the shaft 19.Suitable means, for example springs 50 and 51, tend to keep the valves38 and 46 in cooperation with their seats, i. e. biased t0- Awardclosedposition -in the same manner as the valve 21.

In general, operation of the apparatus may be best understood by firstconsidering diaphragm 30a in extreme left-hand position, .i. e. asdisplaced leftward (from the i.position shown) .to the limit of the riseof the cam 3012. As the cam shaft operates, the diaphragm 30a moves t0the right under the influence of the restoring spring 31a andwithsuctionvalve 21 in open position. A measured amount of slurry willthus be withdrawn from the slurry hopper and admitted into the pumpingand dilution charn- -ber"20. Y

l*By referring to the` timing diagram, Fig. 2, it will be i areasp; y Yi A.

noted that this suction motion of the measuring diaphragm occurs at atime when the suction valve 21 has already been shifted to fully openedposition. It is only after the diaphragm 30a has reached its extremeright-hand position that the suction valve 21 closes. As shown in thetiming diagram, the ushing valves 46 and 38 will be closed at this timeand their period of closure will be terminated after the suction valveis closed and the diaphragm 30a has completed its suction stroke.Thereafter the flushing valves are both opened, the opening operationpreferably occurring during the time the diaphragm 30a is at rest.

Preferably with the aid of the slight ditferentialjn pressure (forexample, 1,/4 lb. per square'inch across the orilce 44) in the waterpipe 35, water will be admitted through pipe 36, through the chamber 37,through the open flushing valve into the dilution chamber 20, and insuch chamber it will dilute (i. e. further dilute) the slurry/previouslythere introduced, and v villthence carry the 'diluted slurry throughpipe 43 into the water in the main35. It

will be understood'that in normal operation the chamber 20 is filledwith water at all times, andthe successive quantities of slurry aredrawn directly into this body of water from the reservoir 10.

Although the diaphragm 30a displaces ina discharge direction during thetravel of flushing water through the dilution chamber 20, it isessentially (in the preferred construction and operation of theapparatus) the. passage of ushing water and not ,the diaphragmdisplacement 'that carries the diluted slurry'to the point` ofapplication in the Waterpipe or main 35; infact in the device shown theslurry would be dischargedevenwithout the diaphragm motion. Thus thediaphragm is moved during this time in the cycle simply to get lit inpositionV to make a suction stroke for the next cycle. y v

In other words, although the diaphragm device-30 goes through themotions of an ordinary pump, its disthe diaphragm, the actual ilow ofliquid in to and from the chamber 20V is usually manytimes that due tothe displacement of the diaphragm.

The timing of the several'pvalves and likewise of the suction andreverseV strokes of the diaphragm 30a,l is illustrated in Fig.; 2, where-a ,single revolution of the low speed shaft 19 is understood vto occurandl where in the diaphragm motion line 60, v the relatively abrupt rise61 represents the suction stroke and the long slop'ej62 the returnstroke. lThe condition of the suction valve`^21 is represented by line63, including its period of opening at 64, while the ilushingvalves areindicated'byithe line 65, these valves being open except during theirinterval of -closure 66, it being understood that the llushing valves 38and 46 arepreferably operated simultaneously, 'and indeed if desired maybe actuated by a single cam rather than by two identical' cams as shown.It will also now be understood that the timing lines 60, 63 and 65 inFig. 2 may be taken to represent, diagrammatically, the configuration ofthe cams 30h, 28, and both of cams 41 and 49, respectively.

As indicated above, the operation of the feeder is simple, positive andetective." The tank or reservoir 10 is filled with the desired liquid,e.' g. a slurry of ne partircles, Which may be as concentrated asdesired. Upon setting the drive in motion, the diaphragm pump 14 is Yingly predetermined Vquantity of slurry from the tank into .thechamberl2,0..l Thereafter the'valv 21 is positively closed, and following itsclosure, the flushing valves 38 and 46 are opened, so that as explained,liquid travels from the line 35 through the chamber 20, back to theline, carrying the slurry along in a diluted form. This cycle iscontinuously repeated, with the effect of a substantially continuousfeed of dilute slurry into the liquid supplied by the line 36 anddischarged through the line 4,3, i. e. specifically in the arrangementshown, into the liquid traversing the main pipe 35. The rate of feed ofslurry is accurately determined by the stroke of the diaphragm 30a andthe rate of rotation of the shaft 19, the amount of slurry supplied perunit time being thus essentially independent of the actual quantity ofliquid that may how through the chamber 20. As the supply in, thereservoir is depleted, further slurry (or its solid and liquidcomponents) may be added at the top of the chamber, without interruptingthe operation of the feeder. Y

It is particularly to be noted that during the opening and closing ofall valves, the diaphragm 30a is at rest, and that the suction valve 21is opened and closed at times when the flushing valves are closed, whilethe op erations of the latter are similarly performed during tends toact like a lter and thus to build up a quantity of particles whichprevent the seat from closing tightly. Experience has shown that thiscondition occurs very seriously with pumping devices that employ reverseflow operated check valves. However, by making sure that flow of liquidthrough the valve aperture has ceased before the valve element is movedtoward closed position, the described diiiculty is substantially orentirelyl obviated, and a much more satisfactory and reliable operationobtained.

` It will also be noted that the present combination includesmechanically operated valves, especially valves of the type having amutually separable valve member and seat wherein closing and opening areeifectuated by displacing the 4member against and away from the apertureseat. When operated in the described timed relation, these valves areparticularly free of difficulties of the sort explained above, andfurthermore the mechanical actuation of the valves is advantageous, in aslurry feeder, in that they may be closed with greater force and thusmore elfectively against obstruction by slurry particles, than isavailable under many operating conditions of conventional check valves.Indeed although the described valve timing is a feature of unusualadvantage, the positively driven closing action of the valves issufficiently effective than in some cases the timing, e. g. of thediaphragmV device 30, need not entirely avoid liquid flow during timesof valve displacement. Thus in some embodiments of the apparatus, alittle flow (as by the final motion of the diaphragm 30a) may even bepermissible through the suction valve 21 when it is closing, especiallywhere the mechanism of the valve 21 is fast and powerful in its actionand thus brings the valve member 23 positively against the seat 22,regardless of any tendency of slurry particles to collect there.

Another feature of preference in the illustrated feeder is thecontiguous arrangement of the reservoir 10 and the flushing chamber 20,allowing the slurry to low, under suction and in measured quantity,directly through an essentially simple port l2 in the intervening wall,rather than through an elongated suction duct or the like.

It will now be seen that the present apparatus affords a particularlyeicient and reliable arrangement for feeding a supplied liquid,especially a slurry, at a controlled or predetermined rate, and in anessentially continuous The gradumanner. The supply .of slurry may bereadily replenished without interruption, while an unusual advantage ofthe feeder is that it can handle very heavy slurries. Indeed presentexperience is that slurries containing as much as 25% to 60% or more ofsolids by Weight, e. g. substances such as diatomaceous earth orpowdered limestone, can be readily and appropriately fed from thereservoir 10, the upper limit of slurry concentration being vapparentlynothing less than a complete loss of lluidity. 'A corollary advantage ofthe handling of heavy slurries is that the apparatus may be relativelysmall and compact, requiring only a small reservoir or tank 1) to supplymaterial, for the ultimate very dilute incorporation in the water orother liquid in pipe 35, as may be 4required over a considerable lengthof time. Y

lt will be understood that the invention is not limited to the specilicapparatus herein shown and described, but may be embodied in other formswithout departure from its spirit.

l claim: l. In a slurry feeder, in combination, a slurry reservoir, areceiving chamber having a common wall with the reservoir and having anopening through said wall into the reservoir, a valve member adapted toclose against and open away from said opening, means including adiaphragm having a face in communication with` `'the chamber, forvarying the volume of the chamber to draw slurry from the reservoirthrough the passage, said chamber having inlet-and outlet means forliquid to receive slurry, valve means controlling the flow through saidinlet and outletV means and means for actuating said firstmentionedvalve member, said second-mentioned valve means and said diaphragm`positively and independently of the pressures acting thereon, saidllast-mentioned means including means timing said diaphragm relative tosaid valve member and valve means to withdraw slurry from the reservoirwhen said valve member is open and said valve means are closed, andmeans timing said valve member relative to said diaphragm and valvemeans to close against said opening when said diaphragm is at rest andsaid valve means are closed.

2. In feeding apparatus, in combination, a variable volume chamber,fluid supply means comprising passage `means communicating with saidchamber, means for cylically increasing and decreasing the volume ofsaid chamber, to withdraw huid from said passage means into the chamberduring intervals of volume increase, valve t means for the passagemeans, liquid supply and outlet means, supply valve means and outletvalve means respectively controlling the ow through said supply andoutlet means and cooperating therewith for passing liquid into, throughand out of said variable volume chamber, valve operating means foractuating the aforesaid passage, supply and outlet valve meanspositively and independently of the pressures acting thereon, and meansconnecting said valve operating means with said volume increasing anddecreasing means for disposing said passage valve means in open positionand said supply and outlet valve means in closed position in intervalsof chamber volume increase, and for disposing the passage valve means inclosed position and the supply and outlet valve means in open positionduring intervals intermediate said lastmentioned intervals.

3. Feeding apparatus as described i'n claim 2, wherein the liquid supplyand outlet means comprises means delivering the liquid from the chamberinto a body of liquid, and means for maintaining a higher pressure inthe supply of liquid to the variable volume chamberthan in thelast-mentioned body of liquid.

4. In feeding apparatus, in combination, a variable volume chamber to belled with a receiving liquid, huid supply means comprising meansproviding a passage into said chamber, said chamber having periodicmeans for alternately increasing and decreasing the volume thereof, towithdraw uid through the passage into the chamber Vduring intervalsofvolume increase, valve means for the passage, liquid supply means andliquid outlet means for passing liquid into, through and out of saidvariable volume chamber, said supply and outlet means respectivelyhaving valve means therefor, valve operating means actuating saidpassage, supply and outlet valve means positively and independently ofthe pressures acting thereon, and means connecting said valve operatingmeans with said periodic means for opening saidpassage valve meansin'intervals of chamber volume increase and for opening the supply andoutlet valve means in intervals of chamber volume decrease, said valveoperating means comprising means for maintaining the supply and outletvalve means closed when the passage valve means is open and formaintaining the passage valve means closed when the supply andy outletvalve means are open.

5. Apparatus as described in claim 4, wherein the outlet means extendsto a body of liquid into which liquid from the chamber is delivered,said liquid suppiy` means, chamber and liquid outlet means constituting,when the supply and outlet valve means are open, a conduit for travel ofliquid to said body, said apparatus including means for advancing liquidalong said conduit, to traverse the chamber under pressure.

6. Apparatus as described in claim 4, which includes a main conduitcan-ying liquid under pressure into which said outlet means extends,said liquid supply means being 'connected to said conduit to draw liquidtherefrom at a locality upstream of the connection of the outlet means,and said conduit having means providing a pressure drop between saidsupply and outlet means, to advance liquid through the variable volumechamber when the supply and outlet valve means are open.

7. Apparatus as described in claim 4, in which said fluid is a slurry,and comprising means including said liquid supply and outlet means andsaid supply and outlet valve means for conveying through said chamberduring each opening of said supply and outlet valve means a volume ofliquid equal to many times the displacement of said periodic means.

8. Apparatus as described in claim 4, in which said fluid is a slurry,and said variable volume chamber has a minimum volume at least severaltimes the displacement of said periodic means.

9. In a liquid feeder, in combination, a liquid reservoir, a receivingchamber to be filled with carrier liquid and y en 8 having a passageopening into the reservoir, saidrchamber havingV volume-varying meansfor alternately increasing and decreasing the volume ofthe chamber, todraw successive quantities of liquid from the reservoir through thepassage during intervals when said volume is increasing, i'nlet meansfor the chamber, outlet means for the chamber, rst, second and thirdvalve means respectively controlling the flow through said passage, saidinlet means and said outlet means, means for actuating each of saidvalves positively and independently of the pressures acting thereon,means connecting all said actuating means with said volume-varying meansfor operation in a mutually timed sequence, for alternately opening saidVsecond and third valve means to pass carrier liquid through saidchamber via said inlet Vand outlet means while the first valve means isclosed, and opening the first valve means to draw liquid from thereservoir into the liquid in the chamber when the chamber Yvolume isincreasing and the second and third valves Yare closed tointerrupt thepassage of carrier liquid through the chamber.

10. A liquid feeder as described in claim 9, wherein the rst valve meansfor the passage comprises a valve seat around the passage and a valvemember in the chamber movable against and away from said seat andwherein each of the second and third valve means for the inletand outletmeans comprises an apertured valve seat and a member movable against andaway from such last-mentioned seat.

11.7Apparatus as described in claim 9, in which the liquid being fed isa slurry, and the valve actuating means cooperates with the connectingmeans to close the passage valve means only at times when the valvemeans for the inlet and outlet means are both closed and thevolume-varying means is at rest, so that no slurry is moving through thepassage valve means when it is closing.

Y References Cited in the tile of this patent UNITED STATES PATENTS1,576,617 Prince Mar. v16, 1926 V2,130,417 Butzler Sept. 20, 19382,216,921 Marvel Oct. 8, 1940 2,238,747 Ornstein Apr. 15, 1941 2,417,372Morris Mar. 11, 1947 Landon Nov. 7, 1950

